#define _CRT_SECURE_NO_WARNINGS
#include"Stack.h"

void STInit(ST* ps) 
{
	assert(ps);
	ps->a = NULL;
	ps->top = ps->capacity = 0;
}

void STDestory(ST* ps)
{
	assert(ps);
	free(ps->a);
	ps->a = NULL;
	ps->top = ps->capacity = 0;
}

void STPush(ST* ps, STDataType x)
{
	assert(ps);
	if (ps->top == ps->capacity) {
		int newcapacity = ps->capacity == 0 ? 4 : 2 * ps->capacity;
		STDataType* tmp = (STDataType*)realloc(ps->a, newcapacity);
		if (tmp == NULL) {
			perror("realloc tmp fail:");
			exit(1);
		}
		ps->a = tmp;
		ps->capacity = newcapacity;
	}
	ps->a[ps->top] = x;
	++ps->top;
}

void STPop(ST* ps)
{
	assert(ps);
	assert(!STEmpty(ps));
	ps->top--;
}

STDataType STTop(ST* ps)
{
	assert(ps);
	assert(!STEmpty(ps));
	return ps->a[ps->top - 1];
}

int STSize(ST* ps)
{
	assert(ps);
	return ps->top;
}

bool STEmpty(ST* ps)
{
	assert(ps);
	return ps->top == 0;
}